Rules Clarification
 

1. When resolves successfully, if the target's combat is not lower than the user's combat, is a -1/-1 coin still placed on the target?
2. Can I remove from game Reinforcement Ninjas in my Discard Pile for the effect of ?

1. Yes, you would still place a -1/-1 coin on the target.
2. Reinforcement Ninjas will never go to your discard pile. If they leave play, they are removed from game.